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Objective: Haemophilus somnus can be involved of bovine
genital system with reproductive problem and it could be isolated from reproductive organs of pregnant and non-pregnant healthy cows.
Design: Prospective study.
Animals: 226 Holstein dairy cows
Procedure: Cows were examined into the 3 groups: 1) Treatment group which was included 103 cows with reproductive diseases. 2) 66 pregnant cows. 3)57 non-pregnant healthy cows. Bacteriological samples were obtained from uterine, cervix and vagina in treatment and non-pregnant healthy cows. However, samples from pregnant cows were obtained from cervix and vagina.
Statistical analysis: Chi-square test.
Results: Haemophilus somnus was isolated from 6(5.82%), 1(1.52%) and 10(17.52%) from treatment, pregnant and non- pregnant group. , respectively. In this study, the highest infectious rate (3.88%) was in treatment group included the uterine tissue. Vaginal infection in non-pregnant group was significantly different from the pregnant and treatment groups (P< 0.025). There were differences between warm and cold seasons of the year in respected to prevalence of the bacteria in the genital system (P< 0.05).
Conclusion: Haemophilus somnus was isolated from 17 (7.53%) out of 226 dairy cows. Cows with reproductive diseases were infected by haemophilus somnus and this bacteria may be the origin of the problems. Haemophilus somnus was isolated from healthy pregnant and non-pregnant cows. J. Fac. Vet. Med. Univ. Tehran. 57, 1: 25-29, 2002.